linux-kernel - [PATCH v5 1/7] misc: sram: fix enabled clock leak on error path

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Date:	Mon, 1 Jun 2015 15:29:54 +0300
From:	Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>
To:	Philipp Zabel <p.zabel@...gutronix.de>,
	Heiko Stübner <heiko@...ech.de>,
	Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC:	<linux-kernel@...r.kernel.org>
Subject: [PATCH v5 1/7] misc: sram: fix enabled clock leak on error path

If devm_gen_pool_create() fails, the previously enabled sram->clk is
not disabled on probe() exit.

Because reserved block logic relies only on information from device tree,
there is no need to get and enable device clock in advance, especially
because not provided clock is not considered as an error, so it is
safe to place devm_clk_get() at the end of probe(). No functional
change.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>
---
Changes from v3 to v4:
- squashed patches v3 1/9 (fix) and 7/9 (clean-up) into v4 1/8

 drivers/misc/sram.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index eeaaf5f..76a23f9 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -90,12 +90,6 @@ static int sram_probe(struct platform_device *pdev)
 	if (!sram)
 		return -ENOMEM;
 
-	sram->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(sram->clk))
-		sram->clk = NULL;
-	else
-		clk_prepare_enable(sram->clk);
-
 	sram->pool = devm_gen_pool_create(&pdev->dev, ilog2(SRAM_GRANULARITY), -1);
 	if (!sram->pool)
 		return -ENOMEM;
@@ -106,10 +100,8 @@ static int sram_probe(struct platform_device *pdev)
 	 */
 	nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
 	rblocks = kmalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
-	if (!rblocks) {
-		ret = -ENOMEM;
-		goto err_alloc;
-	}
+	if (!rblocks)
+		return -ENOMEM;
 
 	block = &rblocks[0];
 	for_each_available_child_of_node(np, child) {
@@ -188,6 +180,12 @@ static int sram_probe(struct platform_device *pdev)
 
 	kfree(rblocks);
 
+	sram->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sram->clk))
+		sram->clk = NULL;
+	else
+		clk_prepare_enable(sram->clk);
+
 	platform_set_drvdata(pdev, sram);
 
 	dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
@@ -196,9 +194,7 @@ static int sram_probe(struct platform_device *pdev)
 
 err_chunks:
 	kfree(rblocks);
-err_alloc:
-	if (sram->clk)
-		clk_disable_unprepare(sram->clk);
+
 	return ret;
 }
 
-- 
2.1.4

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